V groove sheave



July 14, 1953 D, N 2,645,131

V GROOVE SHEAVE Filed April 6. 1949 INVENTOR. Jaw 1'1 721/7.

Patented July 14, 1953 UNITED STATES PATENT OFFICE VGBOOVE SHEAVE David Tann, Detroit, Mich.

Application April 6, 1949, Serial No. 85,834

3 Claims.

This invention concerns a sheave or pulley and it is an object of the invention to provide a relatively thin, light weight sheave possessing a great degree of rigidity, strength and balance. More particularly, it is an object to provide rigidity and strength to a peripheral V groove and to the web portion between the groove and hub of such a sheave.

I have now found that the foregoing and related objects can be secured in a sheave which comprises a crowned web portion; a V groove on the periphery of the crowned web portion, each of the two top edges of the V groove being flanged outwardly; a hub member adapted to be secured to a shaft; and in a preferred embodiment, rib members extending from said hub member to the periphery of the crowned web portion, the apex of the surface described by the crowned web portion lying near a plane defined by the edge of one of the groove flanges.

It is a feature of the invention that advantage may be secured by flanging the ends of the V groove in a manner such that the flanges lie substantially in a common plane.

It is a further feature to provide rib members where the stresses to be encountered by the sheave are particularly heavy and to provide for the arching of said ribs in a manner such that (Cl. i l-230.05)

the outer edges define a surface which is arched oppositely to the crowned web portion. In a preferred embodiment of the invention the apex of the arched surface described by the outer edges of the ribs lies within the space between the two substantially parallel planes defined by the outside edges of the V groove flanges.

It is an additional feature of the invention that additional lightness can be provided in the sheave structure and openings provided for the passage of air by cutting away portions of the surface of the web without sacrifice of strength or rigidity.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a view of a sheave embodying features of the present invention;

Fig. 2 is a cross-section of Fig. 1 taken along the line 2-2; and

Fig. 3 is a cross-section of a rib member and a portion of the crowned web taken along the line 3-3 of Fig. 1.

Referring more particularly to the drawings,

2 a sheave [0 consists generally of an arched or crowned web portion H,- radially disposed rib members [2, a V groove l3 and a hub it. lf'he Web portion H is provided with cut-away portions 15 which are distributed substantially uniiormly over the Web portion and are spaced from both the rib members i2 and the V groove portion IS. The hub I4 is adapted to be secured to a shaft by means of a hole It threaded to receive a suitable screw, the hub being also provided with a lug ll to provide for a greater depth of threads.

The radially disposed rib members 12, extend from the hub [4 to the periphery of the web portion H, the inner edge of each rib member being contiguous with the surface of the web portion. Since it is contemplated that the sheave of the present invention be preferably formed in a single die cast operation, each rib member forms with the web portion a continuous metal phase. Similarly, and in accordance with the preferred mode of construction, the V groove 13 which is positioned on the periphery of the web portion H, will form a continuous metal phase with the web portion.

The V groove i3 is provided with flanges H} which extend outwardly and, as shown, he in substantially the same plane.

As indicated in the drawing, the sheave of the present invention can be constructed of relatively thin metal While maintaining rigidity and strength. By way of example only, a 9- inch diameter sheave with a -inch groove (at widest point of V) can be constructed with a crown radius of about 28 inches and a web thickness of about 0.040 inch. It is preferred that a uniform thickness of metal not be used but rather maximum strength with minimum weight can be obtained by tapering the thickness of the web portion. For example, an average thickness of 0.040 inch is best obtained by a thickness of 0.045 inch near the hub tapering to a 0.035 thickness near the periphery. Similarly and by way of example, the metal of the V groove might taper from 0.045 inch near the bottom of the V to 0.035 inch near the top of the V.

Although ribs may be included or omitted and although the specific dimensions of the sheave may vary in accordance with the use to which the sheave is put, the features of the invention cooperate to provide balance, rigidity and strength in a relatively light-weight structure. One such feature is the outwardly arched or crowned web portion. It is preferred that the center of the surface of the crown Web be located substantially in a plane defined by the outside edge of one of the groove flanges.

Similarly, the rib members, when used in accordance with a preferred embodiment of the invention, may be flat but preferably are arched slightly outwardly in a direction opposite to the arched web portion. By this construction the portion of the rib near the hub is wider than the portion near the groove and greater support i provided thereby at the hub.

Although the V groove flanges may be bent outwardly into a number of positions which increase the rigidity of the structure, I prefer that the flanges lie substantially in a common plane and perpendicular to the two substantially parallel planes defined by their edges.

As indicated above, the combination of the features of the invention permits of the further lightening of the weight of the sheave and the providing of openings for the passage of air by the inclusion of cut-away portions in the web. The openings and the resultant open spoke effect for the passage of air is very desirable when the sheave is used in blower equipment. As shown in the drawings, a number of circular holes may be positioned uniformly in the web portion. It is preferred that about 20% of the web area be cut away to lessen the weight of the sheave. However, any lesser proportion can be cut away with advantage. It will be apparent that the cut away portions may be of a variety of shapes and should be spaced from the rib members and from the V groove in order that maximum strength be maintained.

I claim:

1. A cast sheave comprising a crowned web portion, a circular V groove on the periphery of the crowned web portion, a hub member on the crowned web portion located on the center of the circular V groove, and rib members extending from said hub member to said V groove along the inner periphery of the crowned web portion, the center of the crowned web portion lying substantially in a plane defined by the outer edge at one side of the V groove.

2. A cast sheave comprising a crowned web portion, a circular V groove on the periphery of the crowned web portion, each of the two top edges of the V groove being flanged outwardly to lie in spaced parallel planes, a hub member on the crowned web portion located at the center of the circular V groove, and rib members extending from said hub member to said V groove along the inner periphery of the crowned web portion, the center of the crowned web portion lying near one of said planes.

3. A cast sheave comprising a crowned web portion, a circular V groove on the periphery of the crowned web portion, each of the two top edges of the V groove being flanged outwardly to lie substantially in a common cylindrical surface, a hub member on the crowned web portion located at the center of the circular V groove, and rib members extending from said hub member to said V groove along the inner periphery of the crowned web portion, the inner edges of said ribs being contiguous with the surface of the crowned web portion and the outer edges of said ribs defining a surface which is arched oppositely to the surfaces of the crowned web portion, the center of the crowned web portion lying substantially in a plane defined by the edge of one of the groove flanges.

DAVID TANN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 651,219 Wardwell, Jr. June 5, 1900 767,377 Bowen Aug. 16, 1904 1,009,642 Bruner Nov. 21, 1911 1,175,315 Smith Mar. 14, 1916 1,200,752 Santrock Oct. 10, 1916 1,832,871 Meyer Nov. 24, 1931 2,181,878 Eckleberry Dec. 5, 1939 

